I read the paper "A Study of SAE 5W-30 Synthetic Motor Oils" on Amsoil website.
http://www.amsoil.com/lit/g3115.pdf
My biggest problems are the price they come up with.
Yes, for a 1 quart bottle of M1 5W-30 EP is $9.51 a quart if you buy single quarts. A 5 quart jug of M1 EP can be had for $26.97 at Walmart, this equates to $5.39 a quart. Amsoil's study was geared around 5 quart usage.
Secondly, their mileage of 4777 miles. Who the heck buys M1 EP and then changes it with under 5K miles???!!!! That is wasting money. Only reason to run M1 EP is for the extended drain intervals.
Then Amsoil goes on saying that their Signature Series is good for 25K miles, but they back off stating that under severe service that SS is good for 15K miles. Mobil 1 states that under severe service, follow your owner's manual. From everything I have read, severe service is very much up to interpretation, and every car maker has a different opinion on what is severe.
While I do feel Amsoil is good oil, they do seem to make a lot of assumptions and rely on a lot of lab tests to show how good they are.
What I would like to see is Amsoil conduct REAL WORLD tests of vehicles using Amsoil, Mobil 1 EP, Castrol Edge Ti, etc. I would mention that taxis or other vehicles that are driven very hard would be a good test, but many on here think 80 year old ladies that drive 2 miles to the store and shut the engine off do more damage.
http://www.amsoil.com/lit/g3115.pdf
My biggest problems are the price they come up with.
Yes, for a 1 quart bottle of M1 5W-30 EP is $9.51 a quart if you buy single quarts. A 5 quart jug of M1 EP can be had for $26.97 at Walmart, this equates to $5.39 a quart. Amsoil's study was geared around 5 quart usage.
Secondly, their mileage of 4777 miles. Who the heck buys M1 EP and then changes it with under 5K miles???!!!! That is wasting money. Only reason to run M1 EP is for the extended drain intervals.
Then Amsoil goes on saying that their Signature Series is good for 25K miles, but they back off stating that under severe service that SS is good for 15K miles. Mobil 1 states that under severe service, follow your owner's manual. From everything I have read, severe service is very much up to interpretation, and every car maker has a different opinion on what is severe.
While I do feel Amsoil is good oil, they do seem to make a lot of assumptions and rely on a lot of lab tests to show how good they are.
What I would like to see is Amsoil conduct REAL WORLD tests of vehicles using Amsoil, Mobil 1 EP, Castrol Edge Ti, etc. I would mention that taxis or other vehicles that are driven very hard would be a good test, but many on here think 80 year old ladies that drive 2 miles to the store and shut the engine off do more damage.